Folding apparatus for leading flaps



March 31,*1959 R.'A. LABOMBARDE 2,879,699 f FOLDING APPARATUS EORLEADINGFLAPs Filed Feb. 26, 1957 2 Sheets-Sheet 1 I 5.9 Aeeacz om@o 6278 3,723

0@ "o d 4119 o 63 'Q00 GoGo-@0 INVENToR.-

M, .A RA-YIONDJLLABMBARD 57 v BY j 88 Egg. ab JITI'QRAUZ'YS March 31,1959 R. A. LABOMBARDE 2,879,699

FOLDING APPARATUS EGR LEADING FLAPs Filed Feb. 26, 1957 2 Sheets-Sheet 2n 763g C' y 3 68 Q 67 @fw-W@ 69 66 5,7 72 64 ,53 37 36527 7162 37 Se 4555 2 f4@ 658,5

1f-flhnT 8 4 y 2) "1 *38 6,0 .e3 7 3 ooooooo-oooo0 8 88,.

INVENTOR.

xr'W/l 'f '734mm ATTORNEYS' l United States Patent O 2,879,699 FOLDINGAPPARATUS FOR LEADING FLAPS Raymond A. Labombarde, Nashua, N.H.

Application February 26, 1957, Serial No. 642,606

9 Claims. (Cl. 93-49) This invention relates to machines for folding theleading and trailing aps of flat articles advancing along a path throughthe machine.

In such flat articles, for example paper box blanks, a particulardifficulty arises when the trailing aps are directly behind the leadingflaps so that both follow the same longitudinal path through themachine. This is for the reason that there must be space above the pathin which the leading fiap may be overfolded rearwardly and an overfoldedtrailing ilap will rise up into such space and unfold as it passesthrough the leading flap folding zone. A holddown bar or similarstationary holddown element extending along the leading flap foldingzone to hold down the trailing flaps would, of course, prevent theoverfolding of the leading flaps.

In U.S. Patent 2,764,918 to Leon E. La Bombard of October 2, 1956, a rodrotating in a vertical plane above the path of the articles engages thetrailing flaps and holds them down as the flaps pass through the leadingap folding zone. In my copending applications'Serial No. 448,- 616,filed August 9, 1954, Serial No. 448,720, filed August 9, 1954, nowpatent No. 2,839,972, June 24, 1958, and Serial No. 459,114, filedSeptember 29, 1954, a forwardly hooked folding finger overfolds thetrailing flaps, then vadvances therewith through the leading flapfolding zone While holding the flaps down and then drops below the pathof the articles. In my copending application Serial No. 583,494, led May8, 1956, an untimed hooked folding arm, or member, is provided to engageeach leading ap and overfold the same rearwardly.

This principal object of this invention is to provide an untimed hookedfolding arm arranged to overfold rearwardly each successive leading flappassing thereby and arranged to pass already overfolded trailing aps,without hooking onto the same, by untimed, article actuated means.

Another object of the invention is to provide a hooked folding armarranged to overfold rearwardly each leading ap of each article passingthereby, without timing mechanism but cooperative with timed trailingflap holddown means to move out of the path of said means and the flapsheld down thereby.

A further object of the invention is to provide a hooked folding arm ina leading flap folding zone and a forwardly hooked folding fingeradvancing through said zone to hold down folded trailing iiaps, thefinger lifting the arm lout of the way of the trailing fiaps and thenlowering the arm with greatly diminished rebound effect.

Another object of the invention is to provide longitudinally alignedleading and trailing flap folding mechanism, both operable in a leadingflap folding zone, wherein even an upwardly curled leading flap will beoverfolded rearwardly and wherein no jams occur if the machine skips ablank or is operated without blanks.

Still another object of the invention is to provide a novel mechanismfor the untimed overfolding of leading flaps `of fiat articles advancingalong a path, which mechanism 2,879,699 Patentedv Mar. 31, 1959 ice Fig.l is a fragmentary side elevation, partly in section, of the trailingflap folding zone and the leading flap folding zone of a paper box blankfolding machine. The leading and trailing flaps of a typical blank areshown being overfolded in their respective folding zones.

Fig. 2 is a view similar to Fig. 1 showing theoverfolding at a laterstage.

Fig. 3 is a similar view showing the leading flap completely overfoldedand the trailing flap finger entering the leading flap folding zone. .l

Fig. 4 is a similar view showing the trailing flap finger supporting thehooked folding arm out of the way as it holds down the trailing flapsthrough the leading flap folding zone.

Fig. 5 is a similar View showing the gentle disengage-4 ment ofthetrailing flap finger from the hooked folding arm without rebound of thelatter.

Fig. 6 is a plan view of a flat article having leading and trailingflaps adapted to be folded by the invention.`

As shown in the drawing, 20 represents the frame of a paper box foldingmachine, of a well known type, the machine having one or more lowercarrier belts such .as 21 and one or more upper carrier belts such as 22for advancing flat articles individually and successively along a paththrough the machine such as the paper line 23. Lower carrier belt 21 istrained around pulleys 24 and 25,

a drive pulley 26 and is tensioned by a tension pulley 27.y

Upper carrier belt 22 is trained around pulleys 28 and 29, a drivepulley 30 and is tensioned by a tension pulley 31. Suitable upper andlower presser roll cages 34 and 35 are provided as well as suitablelongitudinally extending twisted folder bars such as 36.

As shown in Fig. 6 a typical at article adapted to be folded by theapparatus of this invention comprises the flat blank 37 which forms acollapsed tray when folded and glued. Blank 37 includes a bottom panel38, side wall panels 39 and 40 having glue tabs 41, 42, 43 and 44thereon and side wall panels 45 and 46 having triangular glue tabs 47,48, 49 and 50 formed therein. The blanks 37 are fed to the machine byany well known type of feeding device and are continuously advancedalong the paper line 23 by upper and lower carrier belts such as 21 and22A with the aps 43, 44 and 46 in the lead and the flaps 41,

42 and 45 trailing. The device of this invention is for thev 55represents a trailing flap folding zone and a trailing ap such as 45 isoverfolded forwardly in zone 55 by trailing flap folding means 56. Eachflap folding means l 56 includes an endless carrier 57 mountedpon frame`2,0 below paper line 23 and driven in synchronization with the drivepulleys 26 and 30. One or more forwardly hooked folding fingers 58 aremounted on,eachnclarrieij "'57 and arranged to overfold the trailingflap such'as 45, aligned therewith, as the finger rounds the rearwardend stretch 59 of the carrier 57.

Each finger then advances along the upper stretch 60 of 1tscarrier ,57at a less rate of speed than the carrier belts 21 `andH 22 so that itholds the folded trailing flap down through the leading ilap foldingzone 62 while the article gradually draws away from thereunder. Near theforward end stretch 63 of each carrier 57 the overfolded trailing flapshave drawn ahead of the linger cornpletely and passed under a holddownbar thus permitting the linger to drop below the paper line 23 on itsreturn path. The operation of the flap folding means 56 is explained indetail in my copending application Serial No. 448,720, filed August 9,1954, but in combination with timed, rotating means for folding theleading aps. As explained insfad application, each finger 58 comprises'a base 61 adapted to be mounted in fixed upstanding relationship on Vanendless carrier such as 57 and the forwardly turned terminal hookedportion in extension of the base 61 is preferably at least equal inlength to the depth of the trailing liap it is designed to overfold.

In this invention instead of timed folding means in the leading vapfolding zone 62 an untimed hooked folding arrnr6`5 `is provided. Thearm, or finger, 65 includes a block 64 mounted on a transverse pivot pin66 above the path of the iiat articles, the pivot pin 66 being carriedby asupport 67 which in turn is angularly adjustable a verticallongitudinal plane on a frame piece 68 by a set screw 69. An arcuatestop member 71 is adjustable by set screw 72 to stop the shank 73 of arm65 at the desired height and cause it to rebound downwardly. A coilspring 74 is also provided on support 67 to resiliently urge the arm 65downwardly. Arm 65 is bent rearwardlyat 'an angle of 90 to form a rightangular notch 75 and its terminal tip 76 is rounded forwardly to enablethe arm to ride along the upper face of objects advancing therebelow. i

A recess 78 is provided lbelow the path of the articles and in the pathof the tip 76 to accommodate the tip when the arm 65 is in its normaldownward position. The leading kedge 79 of each successive article suchas blank 37 is thus guided directly into the notch 75 and furtheradvance of the blank causes a leading flap such as ap 46 to foldupwardly while .pivoting the arm 65 upwardly.y When shank 73 strikesstop 71 the leading ap is forced to fold on its line of fold 52 andfurther advance causes the leading flap to move out from under the armwhile being overfolded downwardly by the spring pressed arm. c

It will be apparent that the terminal tip 80 of a forwardly hookedlinger 58 traveling in alignment'with an untimed hooked arm 65 throughthe zone 62 would catch in the notch 75 and destroyV the arm 65. It willalso be apparentv that if the finger 58 were not aligned with the` arm65 but any portion of an overfolded trailing flap or tab were soaligned, the arrn 65 would catch on such portion and fracture the same.

An untimed actuating arm 82 is therefore fixed to block 64 of thefolding arm 65 and pivotable therewith onthe transverse pivot 66.Actuating arm S2 includes an actuating portionv 83 normally positionedin longitudinal alignment in advance of the notch 75 and above the pathof a flat article advancing along paper linef23. Preferably actuatingportion 83 is normally at about the level of an overfolded Ltrailingflap and tab which level is proximate the level of the tipY 76 of finger58 when advancing along the paper line 23. The leading edge 79 of a flatleading ap such as 45 will thus pass below the `actuating portion 83without engaging-the sarneaand will enter the notch 75 of'folding arm 65for overfolding rearwardly by the arm 65. The overfolded trailing flapof each article is, however, advancing in a higher plane, orat 4a higherlevel, than the main body of the article and, regardless ofhow it is4held down through the leading flap folding zone 62, can be arranged toslidably engage the actuating portion 83 and lift the arms 82 and 65 outof the path of the overfolded trailing ap.

When a forwardly hooked folding finger such as 58 is used it ispreferred that the actuating portion 83 'be engaged by the finger ratherthan the trailing flap as shown in the drawing. In addition it ispreferred that an elongated, protruberance or abutment S4 be provided onthe outer face 85 of each finger 58, the protruberance or abutment 84upstanding therefrom at a substantially uniform height and havinginclined forward and rearward ends 86 and 87 respectively.

In operation as shown in Fig. l each successive flat article such as theblank 37 is advanced continuously along the path formed by paper line 23at a predetermined speed. In the trailing flap folding zone 5S atrailing ap such as 45 is overfolded forwardly by the finger 58 in itsrapid sweep around the rearward stretch 59 of carrier 57. Any diagonaltabs such as 47 and 48 on the flap 45 engage a downfold bar such as 36and are simultaneously overfolded to 45 on their diagonal fold lines ina direction opposite to the fold direction of flap 45. Preferably,during the forward folding operation of finger 58 the leading edge 79 ofeach leading flap such as 46 engages in notch 75 of untimed` folding arm65 and pivots the arm upwardly to overfold the leading flap 46rearwardly. Any diagonal tabs such as 44 and 56 on a flap such as 46 areoverfolded to 45 in the opposite direction by a twisted folding bar suchas 36.

In Fig. 2 the finger 58 is shown advancing along paper line 23 andentering the leading flap folding zone while holding down the overfoldedtrailing ilap 45. Since finger 5S is advancing along the straight upperstretch 60 of carrier 57 it is traveling at less speed than the blank 37and the blank is gradually moving out from under the linger. Hookedfolding arm 65 is completing the downfold of the leading flap 46.

In Fig. 3 the overfolded leading ap 46 has been downfolded and releasedby folding arm 65 and the terminal tip 76 of the arm 65 is spaced abovethe upper face of the main body of the blank 37. The actuating portionS3 of actuating arm 82 is directly in the oath of the linger 58 and thetrailing flap 45 is nearly out from under finger 58 but still being helddown through the' leading ap folding zone 62.

In Fig. 4 the actuating portion 83 of actuating arm 82 is riding alongthe upper face of finger 58 and the ter-- minal tip 76 of folding arm 62is riding along the flat, elongated, straight, upper, or outer, face ofthe protuberance 84 so that both arms are supported, any vibration is-aps have passed under the control of holddown bars or presser cages,the trailing iiap 45 is no longer lheld down by the inger`58 andthe'finger 58 is dropping below the paper line 23 on its returnmovement. It should be noted that while dropping below the paper linethe linger 58 is still supporting the terminal tip 76 of arm 65 andgently deposits the same in the recess 78 to reduce the possibility ofrebound of the arm 65. As shown in Fig. 5 the next successive blank isnow ready to be folded in a similar manner by a second folding finger S8similar to linger 58 and mounted on `carrier` 57.

i The diagonal glue tabs 47, 48, 49 and 5t) travel through the leadingzone in engagement with the 45 face of twister bars such as 36 andarecompletely downfolded by bar-36 beyond theileading ilap zone. Theleading and trailing flaps 41,142, i43 and 44 are overfoldedbysimilarmechanismbut Ain' another zone vnot shown, `this being a wellknown expedient to permitone portion of the at article to `be helddownwhile another portion is being folded.

I claim:

1.- In a machine for` folding .the rleading kand trailing flaps of flatarticles, said machine being of the type having means for continuouslyadvancing said at articles individually and successively along a paththrough a trailing ap folding zone and a leading ap folding zone andhaving trailing liap folding means in said trailing flap folding zone,the combination of an untimed, hooked, folding arm pivotally mounted ona transverse axis above the path of said articles in said leading apfolding zone, said arm having its hooked portion normally below the pathof said flat articles and adapted to intercept the leading edge of, andoverfold rearwardly, each leading ap of an article passing thereunderand an untimed actuating arm pivotable on said axis with said foldingarm and having an actuating portion normally above the path of said liatarticles and in longitudinal alignment in advance of the hooked portionof said folding arm, said actuating portion being in the path of, andslidably engageable by the overfolded trailing flaps of each successivearticle to lift said folding arm out of the path of said overfoldedtrailing flaps.

2. A combination as specified in claim 1 wherein said trailing apfolding means includes a forwardly hooked folding finger advancing intimed relation through said leading liap folding zone while holding downsaid trailing aps, the path of said linger being aligned with saidactuating portion of said actuating arm and said linger being adapted toengage and lift said portion during passage thereby.

3. A combination as specified in claim 2 wherein said hooked folding armand said actuating arm are each curved forwardly at the respectiveterminal tips thereof for riding on the upper face of said hookedfolding finger.

4. A combination as specified in claim 1 wherein said actuating arm andsaid folding arm are both mounted on a block rotatable on saidtransverse axis, and said transverse axis is formed by a transverse pincarried on a support movable angularly in a vertical longitudinal planewhereby the relative heights of said arms may be varied.

5. A device for overfolding the leading aps of flat articles advancingindividually and successively along a path, said device comprising anuntimed, hooked, folding arm adapted to pivot on an axis transverse to,and above the path of said articles for hooking onto the leading edgeportion of a leading liap and overfolding said flap rearwardly and anuntimed actuating arm, in longitudinal alignment therewith fixed to saidfolding arm, said actuating arm having an actuating portion in the pathof, and adapted to be lifted by, any overfolded trailing flaps on saidarticles to thereby pivot said hooked folding arm out of the path ofsaid trailing aps.

6. As an article of manufacture a hooked folding linger for use inoverfolding and holding down the trailing aps on paper box blanksadvancing through a paper box folding machine, said linger comprising abase adapted to be mounted in fixed upstanding relationship on anendless carrier; a forwardly turned terminal hooked portion in extensionof said base at least equal in length to the depth of a trailing ap andan upstanding protuberance extending along the top of the terminal endof said hooked portion, said protuberance being adapted to engage anddisplace an actuating arm in its path and having a at,

straight, elongated, upper face for supporting said ar'm in displacedposition while advancing thereunder.

7. A combination as specified in claim 1 wherein said trailing flapfolding means includes a forwardly hooked folding finger advancing intimed relation through said leading flap folding zone while holding downsaid trailing flaps, an elongated abutment upstanding along the outerface of said folding linger and a liat, straight, elongated, upper faceon said abutment adapted to engage and support the actuating portion ofsaid actuating arm, to deaden the vibration of said folding linger assaid trailing aps pass thereunder.

8. In a machine for folding the leading and trailing aps of flatarticles, said machine being of the type having means for continuouslyadvancing said at articles individually and successively along a paththrough a trailing flap folding zone and a leading liap folding zone andhaving trailing liap folding means including a forwardly hooked foldinglinger advancing through said leading ap folding zone while holding downoverfolded trailing aps and then dropping below the path of saidarticles, the combination of a hooked folding arm pivoted on atransverse axis above the path of said articles in said leading flapfolding zone and adapted to hook onto and overfold rearwardly eachsuccessive leading ap; an actuating arm pivotable in longitudinalalignment with said folding arm and having a portion above the path ofsaid articles and in advance of the hook of said folding arm, and anelongated abutment upstanding from the outer face of said forwardlyhooked folding linger, said abutment being in longitudinal alignmentwith and adapted to engage vsaid portion of said actuating arm, liftsaid actuating arm and said folding arm out of the path of saidoverfolded trailing flaps, deaden the vibration thereof and then engageand lower said folding arm to its flap engaging position withoutrebound.

9. In a machine for overfolding longitudinally aligned leading andtrailing llaps of flat articles the combination of means forcontinuously advancing said flat articles individually and successivelyalong a path with at least one trailing ap of each article following thepath of a leading ap of said article; a hooked folding arm pivoted on atransverse axis above the path of each said leading ap and adapted tohook on to the leading edge thereof to fold each said ilap rearwardly;an actuating arm, longitudinally aligned with, and pivotable with, saidfolding arm; trailing flap folding means along said path adapted to foldeach said longitudinally aligned trailing liap forwardly; mechanismadvancing with said articles past said hooked folding arm for holdingdown said overfolded longitudinally aligned trailing aps; and means,advancing with said mechanism, adapted to engage said actuating arm andthereby pivot said folding arm out of the path of each said trailing apduring its passage by said arm.

References Cited in the le of this patent UNITED STATES PATENTS1,980,604 Von Thien Nov. 13, 1934 2,764,918 La Bombard Oct. 2, 19562,765,714 Wischusen Oct. 9, 1956 2,774,286 La Bombard Dec. 18, 1956

